What is bpy_struct for?
Note that bpy.types.bpy_struct is not actually available from within Blender, it only exists for the purpose of documentation.


In Object Oriented Programming when you define a class you can specify a parent class, your new class then adds some functionality to what the parent class provides.

In blender the bpy_struct is essentially the base class for all classes in blender and provides the core functionality that is common to everything. You cannot use it directly in python but you will often use the functionality it provides in it's many subclasses that you do use.

Examples would be obj.keyframe_insert('location') or pythons standard keys() and values() methods which are implemented in bpy_struct.